"Expectations are rising that China's new leadership will move away from the infamous one child policy. Demographers have been calling for further loosening for years now to slow down the rapid aging of the nation."

China introduced the one child policy in 1979 but has been watering it down over the years. Farmers can have a second child if the first is a girl. If both parents are only children like Zhang and Wu, they can also have two. So what happens if a two child policy kicks in?

"Well if they eliminated it completely or went to a two child policy, I don't think there will be a huge baby boom. Maybe a mini one but it'll quickly be over I think. China is already a relatively prosperous economy, people in the cities already make a kind of level of salary, kind of level of income, where you wouldn't expect them to have five kids."

Despite more lax controls in the countryside, the one-child policy has been very effective, literally cutting the country's birthrate in half in the last 30 years

Some of that's simply because of the high cost of raising a child in China, especially in the big cities. Shanghai for example has one of the lowest birth rates in China

For our one-child couple Zhang and Wu, the decision to have a second isn't easy.